Preheat the oven to 325°F (163°C). Line a 9-inch springform pan with parchment paper and grease the sides.
Mix the crust ingredients, press them into the pan, and bake for 10 minutes. Cool the crust.
Lower oven temperature to 300°F (148°C). Mix cream cheese, sugar, and flour on low speed, then add eggnog, nutmeg, and eggs (one at a time).
Pour the filling into the crust. Bake in a water bath for 1 hour 30-40 minutes. Let it cool in the oven with the door closed for 30 minutes, then crack the door for another 30 minutes.
Chill the cheesecake overnight.
Whip heavy cream, eggnog, and powdered sugar, then pipe onto the chilled cheesecake. Add nutmeg and sprinkles for a festive touch.
Store in the fridge and enjoy within 3-4 days!